def crazy_str(s):

"""

Given a string s, return a crazy looking version where the first

char is lowercase, the second is uppercase, the third is lowercase,

and so on. So 'Hello' returns 'hElLo'. Note that you can use the python .upper() and .lower() methods. The .upper() method returns a string where all characters are in upper case (and analogously for .lower())

>>> crazy_str('Hello')

'hElLo'

>>> crazy_str('@xYz!')

'@XyZ!'

>>> crazy_str('')

''

"""

result = ''